Garmin 3 Plus Manual

Alarms Settings
Clock Alarm uses the internal clock to provide an ‘Alarm Clock’ message at the time 
you set.
To enable/disable the alarm clock:
           1. Highlight the ‘Clock Alarm’ field and press ENTER.
           2. Select ‘On’ or ‘Off’ (as desired) and press ENTER.
           3. If enabling the alarm, highlight the time field (to the immediate right) and press ENTER. Enter the
              alarm time using the rocker keypad and press ENTER.
NOTE: The GPS III+ must be turned on when the alarm...

Position Settings
Position Format is used to change the coordinate system in which a given position 
reading is displayed. The default format is latitude and longitude in degrees and minutes 
(hddd°mm.mmm’). The following additional formats are available:
          • hddd.ddddd° — latitude/longitude in decimal degrees only
          • hddd°mm’ss.s” — latitude/longitude in degrees, minutes, seconds
          • UTM/UPS — Universal Transverse Mercator / Universal Polar Stereographic grids
          • MGRS —...

83
REFERENCE  
Setup Menu: Loran TD
Loran TD Setup Page
Selecting the Loran Chain 
Number
LORAN TD Feature
The LORAN TD (Time Delay) feature eases the transition from using LORAN to using GPS. 
The  III+  unit  automatically  converts  GPS  coordinates  to  LORAN  TDs  for  those  who  have  a 
collection  of  LORAN  fixes  for  favorite  fishing  spots  and  other  waypoints  recorded  as  TDs.  You 
can  display  your  position  as  a  TD  or  enter  waypoints  as  TDs.  The  accuracy  to  be  expected...

REFERENCE  
Setup Menu: Interface
84
Interface Settings
Format lets you control the input/output format used when connecting your GPS III+ to 
external NMEA devices, a DGPS beacon receiver, a personal computer, etc. Five format 
settings are available:
          • GARMIN — the proprietary format used to upload/download MapSource data, 
            exchange waypoint, route, track log data with a PC or with another GPS III+.
          • GRMN DGPS — used to connect the III+ with a GARMIN DGPS beacon...

REFERENCE  
Press MENU to restart the 
scan. 'View Beacon Log' 
allows you to view the last 5  
valid frequencies. To use a fre-
quency from the list, highlight 
it and press ENTER/MARK.
Setup Menu: DGPS
The III+ can automatically 
tune the GARMIN GBR 21 or 
GBR 23.
To have the unit automatically scan for a frequency:
1.  With the unit set to ‘Garmin DGPS’ or ‘RTCM/NMEA’, use the ARROW KEYPAD to highlight 
the 'Tuning Mode' field and press ENTER/MARK.
2.  Highlight ‘Scan’ and press...

The  GPS  III+  can  be  mounted  on  the  dashboard  of  an  automobile  or  to  another 
convenient  surface  using  the  two  Velcro™  strips  provided  with  the  unit. Be  sure  to 
read the warnings on page ii before mounting the GPS in a vehicle!
To mount the GPS III+ using the Velcro strips:
           1.  Select a location for the unit that pro-
vides a clear and unobstructed view of 
the sky.
           2.  Remove the paper strip liners from both 
pieces of Velcro.
           3.  Make sure the...

The GPS III+ is constructed of high-quality materials and should not require user 
maintenance. Should you ever encounter a problem with your unit, please contact your 
GARMIN dealer or GARMIN Customer Service. The GPS III+ has no user-serviceable 
parts. Never attempt any repairs yourself, as this may cause injury or void your warranty. 
To protect your GPS III+, keep it in its carrying case (optional accessory) when not in 
use, and never allow gasoline or other solvents to come into contact with the...

Interfacing formats are selected from the Setup Menu, described on page 84. The input/output 
lines on your GPS III+ are RS-232 compatible allowing easy interface to a wide range of external 
devices, including PCs, differential beacon receivers, marine autopilots and/or a second GPS 
receiver
.
The  NMEA  0183  version  2.0  interface  format  is  supported  by  the  GPS  III+  and  enables  the 
unit to drive up to three NMEA devices:
NMEA 0183 version 2.0 Approved sentences:
GPGGA, GPGLL, GPGSA,...

The  GPS  III+’s  antenna  may  be  removed  to  allow  attachment  of  an  optional 
remote-mounted  antenna.  In  some  applications,  using  a  remote-mounted  antenna 
will dramatically increase the number of satellites received. The GPS antenna should 
be  mounted  in  a  location  which  provides  an  unobstructed  view  of  much  of  the 
sky.  A  minimum  of  four  satellites  are  needed  to  determine  a  three  dimensional  position.  Satellite  coverage  will  vary 
throughout the day, but...

Alarm Clock—The alarm clock time that was set from 
the Alarms submenu has been reached.
Approaching—You are one minute away from reaching 
a destination waypoint.
Arrival at—You have reached your destination 
waypoint.
Battery Power Low—The batteries are low and should 
be replaced.
Data Transfer Complete—The unit has finished 
uploading or downloading information to the connected 
device.
Degraded Accuracy—The unit’s accuracy has been 
degraded beyond 500 meters due to poor satellite geom-
etry or data...